Influence of Vitrectomy-related Factors on the Outcome of Ahmed Glaucoma Valve Implantation

PURPOSE: To evaluate the outcome of Ahmed glaucoma valve (AGV) implantation in eyes with refractory secondary glaucoma following pars plana vitrectomy (PPV) and the associated prognostic factors. METHODS: A total of 146 eyes in 146 patients who underwent AGV implantation after PPV (followed up for ≥1 year) were included. AGV implantation was considered successful when the intraocular pressure (IOP) was 6 to 21 mmHg regardless of using IOP-lowering medication. The hazard ratios (HRs) associated with surgical failure were determined with Cox proportional analysis. RESULTS: The most common cause for PPV was complications of proliferative diabetic retinopathy (50%). The mean and peak IOPs between PPV and AGV implantation were 26.9 ± 6.6 and 35.9 ± 10.2 mmHg, respectively. AGV implantation was performed on average 18.7 months after PPV, and its overall success rate was 80.1% during a mean follow-up period of 43.6 months. In multivariate analyses, rubeosis observed before AGV implantation (HR, 4.07; 95% confidence interval, 1.57 to 10.6; p = 0.004) and higher peak IOP before AGV (HR, 1.04; 95% confidence interval, 1.00 to 1.07; p = 0.034) were predictive of failure. However, no PPV-related factors were associated with the surgical outcome of AGV implantation. CONCLUSIONS: The outcome of AGV implantation is good in refractory glaucoma following PPV. Rubeosis after PPV and higher peak IOP before AGV are risk factors for poor outcomes. Patients who undergo PPV should be followed for the development of rubeosis and IOP control.

Management of Complication after Hyperopic Laser-assisted in-situ Keratomileusis

PURPOSE: We present a case of a patient who underwent corneal refractive surgery to improve their corrected visual acuity due to a complication of hyperopic laser-assisted in-situ keratomileusis (LASIK). CASE SUMMARY: The patient complained of decreased vision after hyperopic LASIK surgery 12 years prior. The corrected distance visual acuity (CDVA) was 20/200 in the right eye and 20/32 in the left, with manifested refractions of +1.25 +2.00 × 90 and -0.25 +2.00 × 80, respectively. The patient had a with-the-rule astigmatism. The values of corneal and total spherical aberration, which can be determined as coefficients of the Zernike polynomials, were respectively -1.027 µm and -0.773 µm in the right eye and -0.965 µm and -0.881 µm in the left eye. Slit lamp biomicroscopy revealed no remarkable findings. We performed surface ablation surgery to flatten the central cornea of the patient's right eye. At 12 months after surgery, the CDVA of the patient's right eye was 20/30 and the negative corneal spherical aberration was reduced. CONCLUSIONS: Corneal refractive surgery to reduce negative corneal spherical aberration by flattening the central cornea is one of possible treatment options for the reduced corrected distance visual acuity after hyperopic LASIK.

Scleral Buckling Using a Non-contact Wide-Angle Viewing System with a 25-Gauge Chandelier Endoilluminator

PURPOSE: To report the outcome of scleral buckling using a non-contact wide-angle viewing system with a 25-gauge chandelier endoilluminator. METHODS: Retrospective analyses of medical records were performed for 17 eyes of 16 patients with primary rhegmatogenous retinal detachment (RRD) without proliferative vitreoretinopathy who had undergone conventional scleral buckling with cryoretinopexy using the combination of a non-contact wide-angle viewing system and chandelier endoillumination. RESULTS: The patients were eight males and five females with a mean age of 26.8 ± 10.2 (range, 11 to 47) years. The mean follow-up period was 7.3 ± 3.1 months. Baseline best-corrected visual acuity was 0.23 ± 0.28 logarithm of the minimum angle of resolution units. Best-corrected visual acuity at the final visit showed improvement (0.20 ± 0.25 logarithm of the minimum angle of resolution units), but the improvement was not statistically significant (p = 0.722). As a surgery-related complication, there was vitreous loss at the end of surgery in one eye. As a postoperative complication, increased intraocular pressure (four cases) and herpes simplex epithelial keratitis (one case) were controlled postoperatively with eye drops. One case of persistent RRD after primary surgery needed additional vitrectomy, and the retina was postoperatively attached. CONCLUSIONS: Scleral buckling with chandelier illumination as a surgical technique for RRD has the advantages of relieving the surgeon's neck pain from prolonged use of the indirect ophthalmoscope and sharing the surgical procedure with another surgical team member. In addition, fine retinal breaks that are hard to identify using an indirect ophthalmoscope can be easily found under the microscope by direct endoillumination.